نشریه نامه انجمن حشره شناسی ایران
سال چهل و سوم شماره 4 (پیاپی 96، پاییز 1402)

The study of animal behavior, particularly in insects, is crucial for understanding their biological and evolutionary aspects, with wide-ranging applications in agricultural science, pest management, conservation biology, and neuroscience. Investigating cognitive characteristics, specifically aversive learning, plays a pivotal role in comprehending the success of insects. This adaptive ability enables animals to efficiently cope with the stressful factors in their environment. In this study, we investigated the aversive learning capabilities of Bombus terrestris Audax workers, crucial pollinators across diverse ecosystems. Bees were trained and tested in a flight arena using artificial flowers equipped with electric shocks to simulate conditions wherebees could associate punishment alongside food resources with available cues. The result suggested that bees possess the ability to simultaneously detect potential threats and food resources, indicating a dual aversive-appetitive memory. Furthermore, comparing groups trained with aversive (electric shock) and neutral (distilled water) stimuli showed that danger cues led to faster learning and stronger memory formation. This conditioning setup aimed to simulate real-life foraging situations, exploring bee responses when confronted with potential dangers. These findings provide insights into the survival strategies of insects in challenging environments that negatively impact bee populations.

Date stone beetles (Coccotrypes dactyliperda Fabricius, 1801) tunnel into palm seeds to establish brood galleries with their larvae consuming the seed’s albumen. Prior work examining the location of the initial penetration holes in de-fleshed seeds had shown a preference for the dorsal groove. This paper presents the data of a follow-up experiment that examined the preferences for penetration holes on complete drupes. Using 100 repeats of a single freshly harvested drupe offered to a single beetle, the study found an overwhelming preference for the beetles to penetrate the drupe at the pedicel scar, with all other sectors significantly less utilised. The implications of this are discussed.

Cellular immunity with the activity of hemocytes is one of the important phases of innate immunity in insects. The role of hemocytes is key in dealing with the stresses and contaminations introduced to the insect hemolymph. These cells react by changing their number, shape, and type during stress. Identifying hemocytes and their diversity is the first step in immunological studies. Humoral defense usually starts with a little delay after cellular immunity, which is associated with the activity of phenol oxidase and antimicrobial peptides. The present study was conducted to investigate the immunology of diapausing and non-diapausing larvae of Megastigmus pistaciae fed on different varieties of pistachio. The pistachio seed chalcid, M. pistaciae, has been one of the key and destructive pests of pistachio in recent years. After collecting infected fruits and transferring them to the laboratory, hemolymph of larvae was extracted and hemocytes were identified after staining with Giemsa solution. Four types of hemocytes were seen in the hemolymph of larvae: prohemocytes, plasmatocytes, granulocytes and oenocytoids. The morphometric sizes of the cells were determined by light microscopy. Differential hemocyte count in hemolymph of larvae, pupae, and adult was determined. The frequency of granulocytes in the larvae was the highest (more than 35±2.4%) and higher than the frequency of granulocytes in pupa and adult. In the study of changes of blood cells in diapausing and non-diapausing larvae feeding on different cultivars, results showed that the hemocyte density of non-diapause larvae that fed on all cultivars was significantly higher than the number of diapause larval hemocytes. In addition, the total hemocyte count, granulocytes, oenocytoids, and prohemocytes in larvae which fed on Kaleghochi and Shapasand cultivars was higher than similar cases on larvae fed on Khanjari, Akbari and Nokhodi cultivars. Changes in phenol oxidase activity in different treatments were similar to changes in blood cells. On the other hand, the activity of this enzyme was higher in non-diapausing larvae than diapausing larvae and more than on larvae that fed on Kaleghochi and Shapasand cultivars as compared with other cultivars. Identification of hemocytes and their changes in diapausing and nondiapausing of pistachio seed chalcid, M. pistaciae, by feeding on different pistachio cultivars, is done for the first time and could be the basis for further studies to identify the immunological characteristics of this pest. It seems that diapause and type of the diet can determine the immune response of the insects against the entomopathogens. Additional research in this field can be effective in the microbial control methods of this pest.

Spodoptera litura (Lepidoptera: Noctuidae) is a polyphagous pest of agricultural crops and causes severe economic loss. In the present study, the biological effect and enzymatic activity of two insect growth regulators, pyriproxyfen and diofenolan was evaluated against S. litura larva. The penultimate instar larvae (0, 24, and 48-hours old) were treated topically at the last three abdominal tergites with sublethal doses (1, 2, and 4µg/µl) of both the juvenile hormonal analogues (JHAs). Several effects were observed such as prolongation in larval-larval and larval-pupal ecdysial duration, larval and pupal mortality, eclosion failure, formation of intermediates, low pupation and reduced adult emergence. Along with these metamorphic catastrophe effects, both JHAs had inhibitory effects for acetylcholinesterase (AChE) but excitatory effects for glutathione –S-transferase enzyme (GST). Whereas, Log IC50 and IC50 values for adult emergence inhibition rate were found to be -0.98 and 0.1 µg/ µl for 24-hours old larvae (Pyriproxyfen); 0.005 and 1.01 µg/ µl for 48-hours old larvae (Pyriproxyfen); -0.085 and 0.82 µg/ µl for 24-hours old larvae (Diofenolan); -0.09 and 1.23 µg/ µl for 48-hours old larvae (Diofenolan). Our result manifests the insecticidal potency of both the IGRs against S. litura.

The diapriid genus, Miota Foerster (Hymenoptera: Diapriidae) is discovered from the first time from the Middle East area, represented by four species in Iran. The specimens were collected using Malaise traps during 2011-2018 in northern Iran. Four newly recorded species were Miota fungorum (Kieffer, 1910), M. monilicornis (Kieffer, 1910), M. polita (Thomson, 1858) and M. thomsoni Wall, 1998. Diagnostic characters, illustrations, geographical distributions, and a key to Iranian species are provided.

Nosemosis is a microsporidian disease caused by Nosema ceranae and N. apis and transmitted via oral-fecal and oral-oral routes. It is globally distributed among adult bees in honeybee colonies. Considering the health importance of nosemosis in honeybees, the study aims to determine the frequency of Nosema spp. infection in migratory apiaries in Hormozgan province by microscopic and molecular methods. In the present study, 20 bees from ten randomly selected hives in 84 migratory apiaries were collected. In the laboratory, the abdomen of the bees was separated from the rest of the body with entomological tweezers and scissors and then ground up in a mortar containing saline serum. The prepared suspension was filtered by passing through a sieve, then the prepared suspension was transferred to test tubes and centrifuged. The pellets were repeatedly washed by saline solution and centrifuged. Finally, the pellets were examined for spores of Nosema spp. by light microscopy and conventional PCR. In microscopy, 38.2 % of apiaries were positive for Nosema spp. spores. By PCR however, DNA of N. ceranae was detected in 39.2. % of apiaries with no samples positive for N. apis. Due to the considerable frequency of infection in migratory apiaries in Hormozgan province, it is necessary to carry out appropriate health measures such as screening of apiaries with appropriate diagnostic methods and training of beekeepers to disinfect hives in order to control Nosema infection in Iranian apiaries by the veterinary health officials.

This study was conducted to determine distribution pattern and related parameters of spotted alfalfa aphid, Therioaphis maculata (Buckten), pea aphid, Acyrthosiphon pisum (Harris) and two coccinellid species (Coccinella septempunctata L. and Hippodamia variegata Goeze) in six alfalfa fields during two growing seasons, 2016 and 2017. Weekly sampling was started when alfalfa plants reached 10 cm in height and continued until harvest. Each field was divided into 20m×20m plots. Two samples per plot per sampling time were randomly taken using a 1 × 1 m quadrat, to count adult coccinellids. Twenty alfalfa stems (longer than 10cm) per plot were randomly cut and shaken eight times on a white pan to record the aphids' density. The aphids that fell into the pan were counted and recorded. The ratio of variance to mean, as well as Taylor’s power law (TPL) and Iwao’s patchiness index (IPI), were used to determine the spatial distribution patterns of the insects. The variance exceeded the mean on all sampling dates, which may imply an aggregative distribution. Aggregation was also confirmed by using regression coefficient of both TPL (parameter b) and coefficient of IPI (β), which both were significantly above unity. Correlation between aphid counts and those of the coccinellids indicated that there was a positive but weak relationship between predator and prey densities in the fields, although a weak correlation may imply that factors other than prey accessibility contribute to the spatial distribution of the predators. Using different statistical methods provides useful information about the spatial distribution and dispersal pattern of aphids and natural enemies in alfalfa fields, and this information can be used in the biological control of pests.

The quarantine pest, Dysmicoccus brevipes (Cockerell) (Coccomorpha: Pseudococcidae) is recorded for the first time on the roots of date tree (Phoenix dactylifera L.) from Ahvaz, Khuzestan province. The adult females and different nymphal instars were found on the aerial roots of date palms varieties during the hot and humid summerof summerof 2023. The pest establishment could represent a serious threat to many subtropical fruits, especially sugarcane, which is one of the strategic products in this area.

Three ladybird (Coleoptera: Coccinellidae) species, Coccinella septempunctata L., C. undecimpunctata L. and Hippodamia variegata (Goeze), were recorded as hosts of Dinocampus coccinellae (Schrank, 1802) (Hymenoptera: Braconidae) in the Iranian provinces of Khuzestan and Kurdistan. Coccinella undecimpunctata is a new host of this parasitoid in the country and both provinces are its new distribution records. The rates of emergence of D. coccinellae from field-collected C. septempunctata and H. variegata were very low (below 1%), while C. undecimpunctata was parasitized to a much higher degree (26.7%).

Trichodes sedlaceki sedlaceki Winkler is newly recorded from Beshgram, Chitral, KPK, Pakistan. Both the genus and the species are new to this region. Figures of the habitus and the aedeagus, along with a distributional map, are presented.