1. Frequently changing climatic conditions can cause recurring droughts which often subject plants to tremendous amounts of stress, leaving biologists to wonder about its impact on the associated herbivores and their interactions with host plants. 2. The present study was aimed at assessing the impact of low moisture stress on herbivore‐plant interactions using tomato and its associated herbivores (leaf miner, Tuta absoluta and sap feeder, Bemisia tabaci). 3. The leaf miner T. absoluta preferred tomato plants exposed to moderate drought stress compared to severely drought stressed or healthy plants while the sap feeder B. tabaci preferred healthy tomato plants that were irrigated regularly over others. Our study uncovers few intriguing aspects of low moisture stress on herbivore‐host interactions and also highlights that this influence may vary depending upon the herbivore feeding guild. 4. The volatile profiles of tomato plants were found to differ significantly when subjected to varied degrees of low moisture stress. Such changes in plant's volatile emissions may in turn alter its associated herbivore's behavioural perspective as observed in T. absoluta and B. tabaci. 5. Reduced amounts of caryophyllene, humulene, 3‐carene, myristic acid, and γ‐butyl‐γ‐butyrolactone might be what aids T. absoluta and B. tabaci in gauging the drought stress status of a host plant. Further, the presence of chemical cues such as α‐pinene, m‐cymene, and ethyl benzaldehyde might signal T. absoluta moths of severely stressed plants. Similarly, the presence of undecane, ethyl benzaldehyde, n‐hexadecanoic acid might aid whiteflies in identifying plants reeling under low moisture stress.

Globally, cucurbit crops constitute over 5.6% of the total vegetable production (Rai et al., 2008). Several insect pests are known to disrupt the production of cucurbits; among them, the melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), is a key pest causing considerable economic loss (Badii et al., 2015;Ekesi et al., 2011). Losses are mainly through fruit-damage by ovipositing female flies, thus decreasing overall yield (Ordax et al., 2015).Presently, control of melon flies is mainly through use of insecticides (Aktar et al., 2009;Dhillon et al., 2005). Although the use of male para-pheromone traps (Cuelure) has proven to be effective in controlling fly population levels, populations can easily recuperate with few males that escape trapping. Therefore, control of female population is desirable as they are the primary reason for damage and future fly populations. There are few lures that attract females and are limited to phago-attractants such as protein hydrolysate and sugars (Jang & Light, 1996). Inopportunely, these lures lack potency, have restricted field life, are arduous to handle and attract non-target species (Jang & Light, 1996). Presently, there are limited

The South American leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a serious pest of tomato causing substantial annual economic losses at a global scale. Our study comprised choice and no‐choice bioassays, aimed at understanding the preference of this oligophagous pest for a few selected solanaceous hosts (tomato, potato, eggplant, ashwagandha, black nightshade, wild tomato, tobacco, and datura), and the identification of the volatile cues that influence its host selection process. In choice assays, T. absoluta females preferred tomato for oviposition over all the other plants, whereas ashwagandha, tobacco, and datura were the least preferred; on datura zero eggs were laid. A similar trend was observed in the subsequent number of larval mines formed. The moth’s preference for host plants of the genus Solanum was quite evident in both the choice and no‐choice assays. Tomato plant volatiles were found to be more attractive to the female moths in single‐ and dual‐choice olfactometer assays. In electroantennographic bioassays, the mean depolarization was significant for tomato, potato, ashwagandha, and eggplant compared to empty air and honey. In total 76 volatile compounds were identified in the GC‐MS analysis across the eight previously selected host–plant headspace samples. Principal component analysis revealed that 1‐fluorododecane and p‐quinone mainly contributed to the observed variation among the host plant volatiles. Of all the host plants, tomato, wild tomato, and tobacco were found to share similarities with respect to volatile cues, whereas ashwagandha, eggplant, and datura were found to be closely related. The other two hosts, potato and black nightshade, had fewer volatiles in common. Volatile cues, namely p‐quinone, 2‐carene, δ‐curcumene, and 1,2‐diethylbenzene, in tomato could serve as oviposition stimulants to T. absoluta, whereas the presence of 1‐fluorododecane in host plants such as datura, eggplant, ashwagandha, and black nightshade, might have deterred T. absoluta from ovipositing. 1‐Fluorododecane was found to be completely absent in tomato.

Oviposition in a generalist parasitoid is a complex process that involves interactions among its host, host plant, and spatiotemporal environment. Our study was aimed at exploring the ability of a generalist parasitic wasp, Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae), in perceiving odor cues from its host insect [Oriental fruit fly Bactrocera dorsalis (Hendel, Diptera: Tephritidae)] in infested mango fruits. A series of experiments involving behavioral and electrophysiological studies suggest that D. longicaudata is able to distinguish host infested fruit volatiles from uninfested. Additionally, we found that D. longicaudata can distinguish between high and low-level infestations using specific cues emanating from fruits. Coupled gas chromatography-electroantennographic detection (GC-EAD) and gas chromatography-mass spectrometry (GC-MS) analysis of infested mango fruit head space volatiles identified compounds such as ethyl butanoate, ethyl 3-hydroxybutyrate, β-myrcene, trans-β-ocimene, allo-ocimene, ethyl octanoate, ethyl-α-toulate, β-elemene, β-caryophyllene, humulene, caryophyllene oxide, ethyl dodecanoate, ethyl hexadecanoate, 2-furancarboxylic acid, 3-hydroxy-2-methyl-4-pyrone, and phenethyl alcohol emanated from three different host treatments with different levels of larval infestation which elicited antennal responses in D. longicaudata. We suggest that these cues might play a significant role in attracting D. longicaudata in the field.

What physiological and neuro-molecular changes control the female oviposition behavior post-mating in insects? The molecular changes that occur in a gravid female insect are difficult to dissect out considering the distinct behavioral patterns displayed by different insect groups. To understand the role of the brain center in Oriental fruit fly, Bactrocera dorsalis oviposition, egg-laying behavior was analyzed in γ-octalactone exposed, decapitated mated B. dorsalis females. Interestingly, the females displayed a possible urge to oviposit, which suggests a natural instinct to pass on the gene pool. Expression analysis of certain genes involved in oviposition behavior was also carried out in these insects to explore the molecular aspects of such behavior. This study tries to assess the involvement of brain center in egg-laying and also explore the role of certain neurotransmitter-related receptors in decapitated B. dorsalis oviposition behavior. Our results indicate that B. dorsalis oviposition behavior could potentially have a bypass route of neuronal control devoid of the brain. The study reported here establishes that decapitation in gravid females fails to abolish their ability to sense ovipositional cues and also to oviposit.