Comparison of infertility of Varroa destructor in resistant and control colonies of the Iraqi honeybee (Apis mellifera meda)

In the current study, the infertility of Varroa mite was compared in resistant (VSH) and control honeybee colonies at the University of Garmian of Iraq. At each stage, the infestation rate, the percentage of fertile mites, the percentage of infertile mites, the number of cells containing mite eggs, and the number of protonymphs and deutonymphs were counted. Percentages of infestation in resistant and control colonies were 6.2 ± 0.9 and 10.9 ± 1.2, respectively. There was a statistically significant difference in the percentage of infested cells between the control and resistant groups (p < 0.05). Moreover, 56.3% of the resistant colonies and 37.50% of the control colonies showed hygienic behaviour (VHS). Resistant colonies showed hygienic behaviour (VHS) regarding the removal of infested pupae and reducing the infestation in colonies compared to control colonies. Mean total infertility in resistant and control colonies were 1.4 ± 0.4 and 1.1 ± 0.3, respectively. Also, the total mean of protonymphs, deutonymphs, and eggs in resistant and control colonies were 0.06, 1.3 ± 0.4, and 2.6 ± 0.8 in resistant colonies and 0.2, 1.3 ± 0.8, and 2.6 ± 1 in control colonies. The results showed that VSH behaviour in adult bees reduces the rate of infestation by Varroa mites in pupas.

Influence of a Neonicotinoid Seed Treatment on a Nontarget Herbivore of Soybean (Twospotted Spider Mite) and Diet Switching by a Co-occurring Omnivore (Western Flower Thrips)

Insecticidal neonicotinoid seed treatments are a common agricultural insect pest management strategy; however, effects on nontarget pests and omnivorous arthropods are understudied. We used a series of experiments to evaluate impacts of the neonicotinoid seed treatment thiamethoxam on densities of herbivorous twospotted spider mites (Tetranychus urticae Koch [Acari: Tetranychidae]) and feeding behavior of western flower thrips (Frankliniella occidentalis Pergande [Thysanoptera: Thripidae]), an omnivore that feeds on spider mite eggs but is also a significant plant pest. Spider mite densities were higher on neonicotinoid-treated soybeans, but only when mites were not spatially confined. We then examined how availability of thiamethoxam-treated food items (i.e., eggs from spider mites reared on treated soybeans, soybean leaf discs, or a combination of the two), and previous exposure to thiamethoxam-treated soybean impacted thrips feeding. Regardless of the presence of leaf tissue, thrips consumed fewer spider mite eggs laid by females reared on treated soybeans, suggesting spider mite eggs can serve as poisoned prey. Overall, thrips consumed less treated soybean leaf tissue, and thrips on treated leaf discs had a lower percentage of herbivorous feeding events and consumed more nontreated spider mite eggs, indicating a dietary shift from herbivory to predation. The neonicotinoid status of spider mite eggs and prior exposure of thrips also caused shifts in the number and size of leaf scars, likely as a result of altered foraging behavior and/or movement. Shifts between herbivory and predation have implications for thrips damage, virus transmission, and pest management, especially in systems with mixtures of nontreated and neonicotinoid-treated plants.

Is Geckobiella stamii (Acari: Pterygosomatidae) a hyperparasite or phoretic on Amblyomma dissimile (Acari: Ixodidae) associated with Iguana iguana from Panama?

In this work, we present the first report of an interaction between Geckobiella stamii and Amblyomma dissimile removed from green iguanas (Iguana iguana) of Panama. From 3045 A. dissimile examined, one larva, two females and one male had mites adhered to the body and 23 female and 3 male ticks had mite eggs on the ventral surface of the idiosoma. The eggs were covered with white finger-like covers. The possible nature of the interaction between G. stamii and A. dissimile is discussed.

Developing risk management treatments for taro from the Pacific Islands

Most taro imported from the Pacific are currently fumigated with toxic methyl bromide to kill pests, predominantly mites and nematodes that are generally found on the surface of taro. Combined high-pressure washing (HPW) and hot water treatment (HWT) were examined as alternative methods for disinfesting taro. Taro mites (Rhizoglyphus sp.) and root knot nematodes (Meloidogyne sp.) were exposed to a range of HWT and HPW conditions separately or together. At 47˚C, mean lethal times of 2.6—2.9 mins and 3.9—4.1 mins were estimated to control 99% and 99.99% of nymph and adult mites, respectively. Mite nymphs and adults were more tolerant to HWT than mite eggs. The mean lethal time estimate to control 99% of juvenile nematodes was 4.5 mins. Nematode eggs were the most tolerant life stage with only 10% mortality after a 4-min 47˚C HWT. HPW+HWT reduced heavy infestations of mobile pests on taro (n=30—117/taro) by 100%. HPW followed by HWT 50˚C for 12.5 mins reduced viable egg infestation by 95.8%. HPW followed by HWT can control surface pests on taro while maintaining taro quality.

Orius albidipennis (Heteroptera: Anthocoridae): Intraguild predation of and prey preference for Neoseiulus cucumeris (Acari: Phytoseiidae) on different host plants

A widespread interaction in natural enemy populations is intraguild predation (IGP), the intensity and outcome of which may be influenced by several factors. This study examined the influence of host plant characteristics on IGP between Orius albidipennis (Reuter) and Neoseiulus cucumeris (Oudemans) in laboratory experiments. The intraguild predation between the two predators was bi-directional, but predation by N. cucumeris on O. albidipennis is presumably of negligible importance. Orius albidipennis preyed uponmite eggs and adults in the absence of Thrips tabaci (Lindeman) (Thysanoptera: Thripidae), but in its presence predation on mite eggs was abandoned and predation on adult mites unchanged (sweet pepper) or reduced (eggplant, cucumber). The IGP-level of O. albidipennis on N. cucumeris was highest on sweet pepper and lowest on cucumber. Inclusion of host plant aspects in evaluations of the IGPpotential between predators intended for simultaneous applications for biocontrol is thus of importance.

A large parasitengonid mite (Acari, Erythraeoidea) from the Early Cretaceous Crato Formation of Brazil

A new large, fossil mite (Arachnida: Acari), Pararainbowia martilli n. gen. n. sp., is described from the Early Cretaceous (Aptian) Crato Formation from Ceará State, Brazil. It is assigned to the Cohort Parasitengona and the superfamily Erythraeoidea, some extant members of which can reach up to seven millimetres in body length. Given that doubts have been raised about the identity of putative Crato feather mite eggs, this new fossil represents the first unequivocal record of Acari from the Crato Formation, the first non-amber record of an erythraeoid mite and the oldest named example of this superfamily. Fossil erythraeoids from Mesozoic and Tertiary ambers are briefly reviewed – including a widely overlooked Late Cretaceous species – with comments on Mesozoic mites in general. Thirteen Baltic amber erythraeoids have been formally described, but much unstudied material from various amber sources remains. Ein neues großes Milbenfossil (Arachnida: Acari), Pararainbowia martilli n. gen. n. sp., wird aus der Crato Formation (Unterkreide, Aptium) des Ceará Gebietes in Brasilien beschrieben. Es wird der Kohorte Parasitengona und der Überfamilie Erythraeoidea zugeordnet; die modernen Vertreter erreichen eine Körperlänge bis zu sieben mm. Weil die Identität von Federmilbeneiern aus der Crato Formation in Frage gestellt wurde, ist dieser Neufund der erste klare Hinweis von Acari aus der Crato Formation. Es ist die erste erythraeoide Milbe, die nicht aus dem Bernstein stammt sowie das älteste genannte Beispiel dieser Überfamilie. Fossile erythraeoide Milben aus dem Bernstein des Mesozoikum und des Tertiärs werden kurz zusammengefasst – u. a. eine weitgehend übersehene Art aus der Oberkreide – mit allgemeinen Anmerkungen zu den mesozoischen Milben. Dreizehn erythraeoide Milbenarten sind aus dem baltischen Bernstein genannt und beschrieben worden, aber weiteres unbearbeitetes Material von verschiedenen Bernstein-Fundpunkten liegt noch vor. doi:10.1002/mmng.200700001