Abstract "The survival ability of insects can be limited with the changes in the levels of energy metabolites under stressful conditions but only a few studies have considered the plastic effects of heat and related climatic factors relevant to tropical habitats. The objectives of our study were to determine whether adults of Zaprionus indianus are capable of rapid heat hardening (RHH) and rapid desiccation hardening (RDH) and to compare its benefits with heat ac climation (HA) and desiccation acclimation (DA). Adult flies reared under season-specific simulated conditions were subjected to 38˚C for RHH and 32˚C for HA, while 5% relative humidity (RH) was maintained for RDH and 40% RH for DA. Stress-induced effects of heat and desiccation on the levels of five metabolites namely cuticular lipids (CL), total body lipids (TBL), protein, proline, and carbohydrates were then estimated by biochemical method. Dif ferent duration of heat hardening and acclimation led to more accumulation of CL whereas different durations of desiccation hardening and acclimation revealed less accumulation. In contrast, there was an accumulation of carbo hydrates and protein under desiccation hardening and acclimation whereas there was the utilization of carbohydrates and protein under heat hardening and acclimation. However, mixed results were observed on the level of pro line and TBL under both heat and desiccation stress. These stress-triggered changes in the levels of various metabolites suggest a possible link between heat and desiccation tolerance. Hence, these compensatory changes in the level of various metabolites also suggest possible energetic homeostasis in Z.indianus living under harsh climatic conditions of heat and drought in tropi cal regions."

Abstract Background: Understanding the biology of Anopheles malaria vector species is essential to planning effective and sustainable malaria control strategies in endemic countries. This study reported the implication of Anopheles leesoni in malaria transmission in Cameroon, Central Africa. Methods: Mosquitoes were collected in three localities from May 2015 to March 2018 using electric aspirators and Centers for Disease Control light traps (CDC-LT). Anopheles funestus sensu lato (s.l.) mosquitoes were identified as species using poly merase chain reaction assay (PCR). Furthermore, Plasmodium falciparum infection status was determined using the enzyme-linked immunosorbent as say (ELISA) method. Results: A total of 12,744 Anopheles mosquitoes were collected by electric aspirator (N = 4844) and CDC-LT (N = 7900). Anopheles funestus s.l. (86.95%) was the major species and the main malaria vector in rural savannah and rural forest sites followed by A. gambiae s.l. (13.05%)whereas in urban areas, A. gambiae s.l. was by far the most abundant repre senting 91.45% of Anopheles mosquitoes collected. Two members of the A.funestus group were identified among 1389 analysed by PCR: 1307 A. funes tus sensu stricto (s.s.) (94.10%) and 82 A. leesoni (5.9%). Plasmodium falci parum infection rate was 21.04% in A. funestus s.s. For the first time, A leesoni was found positive for P. falciparum (infection rate: 10.98%) in Cam eroon. Conclusion: A very high P. falciparum infection rate was observed in this study in A. funestus s.s., highlighting its high implication in malaria transmission in Cameroon. Furthermore, the detection of P. falciparum in fection in A. leesoni calls for more attention towards this neglected vector species.

Abstract Sitophilus zeamais is a primary pest of stored maize, which can cause quality and quantity losses. Maize is cultivated in several West African countries where different agro-climatic and agro-ecological conditions exist. These conditions could influence the Sitophilus zeamais morphology. Thus, the purpose of this study is to identify the Sitophilus zeamais morphological groups in the four countries. This was carried out through the morphometric study of 30 male Sitophilus zeamais individuals taken from the yellow maize in each country, by measuring with a binocular magnifying glass, 16 variables of the different tagmas belonging to the insect. Subsequently, statistical analyses were firstly carried out with the raw measurements, such as the prin cipal component analysis, in order to extract the contribution of the variables on each factorial axis and to visualise the correlations between the variables. Taking the case of the transformed measurements, in addition to the princi pal component analysis, a discriminant factorial analysis was carried out to find out the best factor for gathering individuals according to their morphol ogy, a confusion matrix to summarise the individual’s reclassification in or der to deduce the good and bad classification rates, and an ascending hierar chical classification which consists of gathering the individuals according to their similarity and separating them according to their dissimilarity using the truncation method. Therefore, five morphological groups were identified. However, the existence of these morphological groups would not be linked to agro-ecological, climatic conditions and to the geographical remoteness be tween countries.

Abstract Objective: The objective is to compare a regular ovitrap versus an innovated larvitrap for monitoring Aedes spp. populations. Materials and Methods: A total of 20 regular ovitraps and 20 innovated larvitraps were placed in pairs in 20 houses from the 5 de Febrero neighborhood in Tapachula, Chiapas, Mex ico. The innovation consisted in the incorporation of a valve in the lower part of a half tire to drain the contents in a 2 L collection container. The evalua tion was carried out during five weeks, collecting eggs and larvae from the ovitraps and innovated larvitraps, respectively. Positivity indexes and insec tary production of adult Aedes spp. mosquitoes were compared by collection type. Results: Average positivity index for the five weeks period were 60% for ovitraps and 91.25% for innovated larvitraps. During the five weeks, 4043 Ae.aegypti and 703 Ae. albopictus adult mosquitoes were produced in the insec tary from the eggs collected from ovitraps, while from innovated larvitraps were 9014 Ae. aegypti, 1205 Ae. albopictus, and 15 Culex spp. Conclusion:Collection by the innovated larvitrap was more efficient, collecting 3.56 times more Ae. aegypti than with ovitraps, using approximately the same effort in time for replacing the filter paper from traditional 1 L ovitraps. Since the lo gistics for the storage and placement of larvitraps may still be a disadvantage in comparison with ovitraps, their use could be specifically intended in senti nel sites for mosquito population monitoring for entomological surveillance purposes.

Abstract Aedes-borne diseases remain a public health challenge for many countries globally. The extent of spread of invasive species of Aedes mosquitoes and risk of transmission of the diseases especially around the point of entry of goods such as ports is not well known in Ghana. This study investigated the ecology, distribution and risk of transmission of viral haemorrhagic fevers by Aedes mosquitoes around the port areas of Tema, Southern Ghana. The mosquitoes from this study were collected using human landing catches, ovitraps and larval collections for a period of six months. A total of 1092 containers were inspected in both seasons and of these, 237 (21.7%) were positive for mosquito larvae or pupae in rainy season while 181 (16.6%) were positive in dry season. A total of 6498 mosquitoes were collected and identified morphologically using taxonomic keys. 6038 (92.9%) were Aedes aegypti, 337 (5.2%) were Culex spp. and 123 (1.9%) were Anopheles gambiae. The Ae. aegypti larvae were found breeding in a series of water-holding containers which included disposed plastic containers, earthenware pots, car tyres, plastic barrels, plastic basins, buckets, metal drums, jerrycans and poly tank. A high proportion of Aedes aegypti eggs were found in the ovitraps during the rainy season than in the dry season in the study sites. Ae. aegypti was the most common mosquitoes biting mostly outdoors (65.6%) with more bites occurring in the rainy season (63.6%) in the two residential sites (Tema Community One and Tema New Town). The risk of transmission of viral haemorrhagic fever in the study sites was assessed using House Index, Container Index, Breteau Index and was found to be higher in Tema New town area with seasonal variations within the sites. The man-vector contact rates for the two residential sites were also found to be higher in rainy season than the dry season. These observations indicate that the risk of transmission of viral haemorrhagic fevers in the study areas is high especially in the rainy season. The implications of the findings in the formulation of future vector control programmes around the port areas in the country are discussed in the paper.

Abstract Bemisia tabaci has a wide range of host plants. Due to its short-distance solid migratory ability, there is a phenomenon of migration and damage among plants in different seasons. Through the study of the population growth and decline rules of B. tabaci on different host plants and the prediction and forecast technology explores its sustainable prevention control technology. This article mainly discusses the research progress of B. tabaci forecasting, realizing the timely prevention and control of B. tabaci and comprehensive regional management, which can effectively reduce the population base of B. tabaci and reduce the number of pesticides used, which has a protective effect on the ecological environment.

Abstract Termites are social insects that live in colonies underground. Globally, there are 3000 termite species, of which 39% are found in Africa. Termites are used as food and livestock feed in most communities of the world. In Kenya, termites are consumed by many communities, especially in the western region. Termite species diversity across different parts of the Luanda sub-county was established as there are many edible and non-edible species in the area. This study assessed the species diversity of termites in Luanda sub-county, and characterized them morphologically. Termites were sampled in Luanda sub-county using the line transect method. The collected termites were preserved in tubes containing 70% Ethanol. The preserved samples were taken to the National Museums of Kenya for morphological identification up to species level. Species richness of each habitat was analyzed for diversity (Shannon-Wiener) index and Shannon index by using Vegan package version 1.16 - 32 in R. The differences in species composition and diversity of termites were analyzed using one-way ANOVA. Morphological identification recorded seven species, namely, Macrotermes herus, Macrotermes spp1, Macrotermes sp1, Pseudocanthotermes grandiceps, Macrotermes bellicosus, Macrotermes spp2 and Pseudocanthotermes militaris. The results of this study showed that the Shannon diversity index H was 0.3606 while Simpson index D was 0.20644, which implied a high species diversity of termites in Luanda sub-county a leading producer of edible termites in Kenya.

Abstract This study aims to ascertain the extent of the cocoa stem borer Eulophonotus myrmeleon distribution, outbreak, and damage to the cocoa plantations in six cocoa growing states in Nigeria. Three local government areas were selected from each of the six major cocoa states and three farms from each local government area. In each farm, 100 cocoa trees were randomly selected and inspected for symptoms and damages of E. myrmeleon. The result revealed that E. myrmeleon infestation has increased significantly (p = 0.01, df = 1, F = 41.77) in 2019 by 10% from the 2014 inspection. It also showed that the infestation level was significantly different from state to state. Symptoms of infestation include presence of entry/exit holes, woody exudates around the trees, yellowing and browning of the leaves. Damages caused by E. myrmeleon infestation are, loses of pod on the affected branch and tree and death of tree. Field observations showed clearly that stem borer is now becoming a serious problem and limiting considerably the production of cocoa in the region. It is time to give more attention to the biology and management of the pest. This is the first report detailing the symptoms and damage done by cocoa stem borers in Nigeria.

Abstract Information on Culex mosquitoes (vectors of filarial worm and viral encephalitis) from northern Nigeria is scanty, hindering evidence-based control. Here, two Culex populations (Kano and Kaduna) were characterized. Culex quinquefasciatus and Culex pipiens were found breeding in sympatry, with some hybrid individuals identified. Larval bioassays revealed high temephos resistance (LC50s = 1.34 mg/mL and 3.01 mg/mL for Kano and Kaduna, respectively). Larvae were more sensitive to α-cypermethrin (LC50s = 0.026 mg/mL and 0.067 mg/mL for Kano and Kaduna). WHO adult tube bioassays revealed high pyrethroid and DDT resistance, with mortalities of 44.01% ± 6.79%, 35.83% ± 12.58%, 29.69% ± 9.97% and 52.47% ± 4.34% for permethrin, deltamethrin, α-cypermethrin and DDT, respectively. Highest resistance was observed with bendiocarb (mortality = 13.58% ± 3.98%). High resistance was obtained with fenitrothion and malathion (mortalities = 21% ± 4.76% and 56.47% ± 8.67%, respectively), while a full susceptibility was observed with pirimiphos-methyl. Pre-exposure to piperonylbutoxide (PBO) significantly recovered α-cypermethrin susceptibility (mortality = 82% ± 5.16%, χ2= 50.99, p < 0.0001), compared with the conventional bioassay (mortality = 32 ± 7.30). Mortalities of <20% were obtained in cone bioassays with Yorkool, DuraNet and PermaNet3.0 (side panels) nets, suggesting a loss of efficacy of conventional long-lasting insecticidal nets. However, mortalities of 99% and 86% were obtained in Kano and Kaduna populations using the roof of PermaNet3.0 (containing PBO and deltamethrin). Despite the high frequency of the 1014F VGSC knockdown resistance mutation allele (0.90), no correlation was observed between the 1014F kdr genotype and resistance phenotype. Sequencing of fragments of the acetylcholinesterase-1 gene detected no G119S mutation, in malathion-alive and malathion-dead females. These suggest a preeminent role of metabolic resistance in these Culex populations.

Abstract Cowpea seed constitutes an important source of proteins for populations in Sub-Saharan Africa. But this food resource is heavily damaged by cowpea beetle Callosobruchus maculatus. The control of that pest is mainly carried out by using synthetic insecticides. Despite the efficacy of this method, it caused environmental and health problems. Therefore, the search for alternative methods is vivaciously needed. In this issue, the bio-efficacy of Plectranthus kirbii extracts was assessed on C. maculatus regarding adult mortality, suppression of population and grain damage as well as seed viability preservation and repellency. The leaf powder and aqueous extracts of the plant were tested at 2, 4, 8 and 16 g/kg on bruchid adult for toxicity and damage bioassays. Repellency test was carried out using the plant aqueous, methanolic and ethyl acetate extracts at 0.5, 1, 2 and 4 mg/cm2. The seed viability was evaluated using seeds preserved for three months at the single concentration of 16 g/kg of each plant extract. Significant mortality of cowpea beetle was induced by the plant aqueous extract and leaf powder. LC50 values decreased with the increasing exposure period, and aqueous extract and leaf powder recorded 33.42 and 9.48 g/kg respectively within 3 days whereas within 5 days, the same extracts in the same order recorded LC50 of 1.31 and 8.73 g/kg respectively. These extracts significantly reduced damage by suppressing almost completely the bruchid population growth. The non-infested grain preserved recorded high grain viability compared to the infested ones. The non-treated infested recorded the lowest germination rate (11.33%). The repellency rate ranged from 38.75% to 83.75%. Ethyl acetate and methanolic extracts were classified as the class III repellent product, while aqueous extract ranged as class IV in repellency. Considering these findings, the extracts of P. kirbii could favourably replace the synthetic insecticides used in the cowpea protection during storage.