Hopkins Host-selection Principle Research Articles

Host Choice and Feeding Behaviours of Glossina morsitans Offspring Whose Parents Were Fed on Different Host Species

The success of any tsetse control program depends on the knowledge of their behaviour. This study assessed the host choice and feeding behaviours of Glossina morsitans siblings whose parents were bloodfed on rabbits, guinea pigs, rodents, and squirrels. Each individual host was placed in a screen cage, which allowed flies to enter through openings on each side. The groups of flies (20 per replicate), which were colour-marked differently based on their parents’ blood meal hosts, were released from the centre of large semi-field cage. The released flies were aspirated after 24 h and then sorted based on their location, feeding status, and parents’ blood meal. A total of 213 flies (72.95% of those recovered) were attracted to the hosts. The numbers of flies attracted to different hosts varied significantly (χ24 = 33.685, p = 0.0001): rodents (n = 80, p = 0.006), rabbits (n = 59, p = 0.331), guinea pigs (n = 49, p = 0.057), and squirrels (n = 25, p = 0.005). The numbers of flies attracted to their parent’s blood meal source varied significantly (χ212 = 56.476, p < 0.001): rabbits (n = 35, 59.32%, p < 0.001), rodents (n = 25, 31.25%, p = 0.043), and guinea pigs (n = 19, 38.78%, p = 0.45). But only 39 flies (18.31% of the total attracted) bloodfed on the hosts, including guinea pigs (n = 10, 25.64%), rodents (n = 23, 58.97%), rabbits (n = 6, 15.38%), and squirrels (n = 0, 0.0%). There was significant variation in the number of flies that fed successively across hosts (χ24 = 49.478, p < 0.001). The findings from this study confirm the presence of differential attractiveness of the hosts to flies and the so-called “Hopkins host selection principle” or “pre-imaginal conditioning”. Therefore, the study attracts the need for detailed investigation on the influence of blood meal sources on tsetse fly siblings’ behaviours across filial generations using small mammals or other large mammal species.

Larval experience of stable fly, Stomoxys calcitrans Linneaus, 1758 (Diptera: Muscidae) does not influence oviposition preference in gravid females

1. Hopkins' host selection principle (HHSP) proposes that, in holometabolous insects, gravid females prefer to oviposit on their developmental substrate. This hypothesis is widely explored in phytophagous insects, but few studies have considered blood‐feeding insects. In this study, the HHSP was tested using the haematophagous stable fly, Stomoxys calcitrans (Diptera: Muscidae). Using no‐choice and two‐choice tests, the study first sought to demonstrate whether S. calcitrans larvae recognise their rearing substrate.2. It was found that when a rearing substrate is offered to S. calcitrans larvae singly (no‐choice) or associated with a non‐rearing substrate (two‐choice), they were able to recognise the substrate in which they developed. This ability disappeared when larvae were transferred to another substrate for 5 h.3. Next, using oviposition bioassays, it was investigated whether information gathered by pre‐imaginal stages during their development can persist into the adult stages after metamorphosis. It was hypothesised that gravid females emerging from clean and uncleaned pupae reared on sheep and camel dung would still prefer to lay on their rearing substrate. The results revealed that gravid females did not prefer to oviposit on their developmental substrate. In addition, failure to recognise and prefer their developmental substrate was found in gravid females that had emerged from puparia that were cleaned as well as those contaminated with sheep dung.4. It is concluded that S. calcitrans adult preference is not influenced by their offspring's experience. Overall, the HHSP was not supported by our study, suggesting that this principle may not apply to generalist insects characterised by high plasticity in oviposition substrate acceptance.

The effect of Achyranthes japonica extract on larval survival and development and oviposition behavior of Plutella xylostella L. (Lepidoptera: Plutellidae)

The extract of Achyranthes japonica was tested for effects on larval survival and development and the oviposition behavior of the diamondback moth, Plutella xylostella L. Chinese cabbage dipped in A. japonica extract solution showed 51–80% antifeedant activity for 5days against P. xylostella larvae, and more larvae were also on untreated cabbage leaves 24h after release. The mortality of P. xylostella larvae increased proportionally to the duration of dipping time in the extract, and both pupation and emergence rates of larvae feeding only on treated cabbage were lower than those for larvae raised on untreated or with a choice of cabbage. The 20-hydroxyecdysone (20E) concentration in leaves was approximately 549, 1232, 1275, and 1426μg/g at 6, 12, 24, and 48h after dipping treatment, respectively. Notably, naive females laid more eggs on untreated cabbage than on treated cabbage, and females from larvae raised on treated Chinese cabbage also preferred the non-treated leaves. Our results are in contrast to those from earlier studies using various insect models that confirmed most females prefer to lay eggs on the host type that was eaten in the larval stage (Hopkins host selection principle). Cabbage dipped in the A. japonica solution for 24h caused 59% larval mortality and inhibited both pupation and emergence rates of the larvae when exposed to plants 15 and 22days after planting in the field, with the 20E concentration in the treated cabbage leaves at 1600.9±122.36 and 1386.8±24.69μg/g, respectively. Therefore, the biological effectiveness could be attributed to the 20E in the treated cabbage leaves.

Influence of Dietary Experience on the Induction of Preference of Adult Moths and Larvae for a New Olfactory Cue.

In Lepidoptera, host plant selection is first conditioned by oviposition site preference of adult females followed by feeding site preference of larvae. Dietary experience to plant volatile cues can induce larval and adult host plant preference. We investigated how the parent’s and self-experience induce host preference in adult females and larvae of three lepidopteran stem borer species with different host plant ranges, namely the polyphagous Sesamia nonagrioides, the oligophagous Busseola fusca and the monophagous Busseola nairobica, and whether this induction can be linked to a neurophysiological phenotypic plasticity. The three species were conditioned to artificial diet enriched with vanillin from the neonate larvae to the adult stage during two generations. Thereafter, two-choice tests on both larvae and adults using a Y-tube olfactometer and electrophysiological (electroantennography [EAG] recordings) experiments on adults were carried out. In the polyphagous species, the induction of preference for a new olfactory cue (vanillin) by females and 3rd instar larvae was determined by parents’ and self-experiences, without any modification of the sensitivity of the females antennae. No preference induction was found in the oligophagous and monophagous species. Our results suggest that lepidopteran stem borers may acquire preferences for new olfactory cues from the larval to the adult stage as described by Hopkins’ host selection principle (HHSP), neo-Hopkins’ principle, and the concept of ‘chemical legacy.’

Larval host plant origin modifies the adult oviposition preference of the female European grapevine moth Lobesia botrana

According to the 'natal habitat preference induction' (NHPI) hypothesis, phytophagous insect females should prefer to lay their eggs on the host species on which they developed as larvae. We tested whether this hypothesis applies to the breeding behaviour of polyphagous European grapevine moth, Lobesia botrana, an important pest in European vineyards. We previously found that different grape cultivars affect several life history traits of the moth. Because the different cultivars of grapes are suspected to provide different plant quality, we tested the NHPI hypothesis by examining oviposition choice of L. botrana among three Vitis vinifera cultivars (Pinot, Chasselas and Chardonnay). In a choice situation, females of L. botrana that had never experienced grapes were able to discriminate between different grape cultivars and preferentially selected Pinot as an oviposition substrate. This 'naive' preference of oviposition could be modified by larval environment: Females raised on grapes as larvae preferred to lay eggs on the cultivar that they had experienced. Furthermore, experience of the host plant during adult emergence could be excluded because when pupae originating from our synthetic diet were exposed to grapes, the emerging adults did not show preference for the cultivar from which they emerged. The NHPI hypothesis that includes the two sub-hypothesis "Hopkins host selection principle" and "chemical legacy" may thus be relevant in this system.

Absence of Learning and Local Specialization on Host Plant Selection by Heliconius erato

There is considerable interspecific variation in larval host plants (Passifloraceae) used among Heliconius erato (Lepidoptera: Nymphalidae) populations. This study evaluates the role of learning and the influence of interspecific variation in host plant attributes on such local specialization in H. erato host plant choices. Experiments were conducted under laboratory, insectary, and field conditions, with the two most widely used host plants in southern Brazil (Passiflora suberosa Linnaeus and Passiflora misera Humbold, Bonpland et Kunth). Larval feeding preference and induction were evaluated through choice tests for all instars. Oviposition was evaluated in relation to host plant preference, Hopkins host-selection principle, and conditioning time (for 3, 7, 11, or 15 days). Also, oviposition choice was tested regarding density, intemode length, and presence of intact terminal bud on P. suberosa and P. misera shoots. Both larvae and adults of H. erato phyllis showed preference for P. misera compared to P. suberosa, under all conditions. Larval feeding preference could not be induced for most instars. The Hopkins’ effect was not detected and oviposition choice could not be conditioned. Females alternated use of host plant species as a function of variation in either density or presence of terminal buds on shoots. Thus, our data indicate host plant preference in H. erato phyllis is not learned but innate. Therefore, we concluded that variation in local use of host plant by this butterfly in southern Brazil results from qualitative and quantitative variation of the passion vine species.

Inheritance and plasticity of adult host acceptance in Yponomeuta species: implications for host shifts in specialist herbivores

AbstractChanges in host acceptance is an important factor in the host specialization of phytophagous insects, and knowledge of the genetic organization of this behaviour is necessary in order to understand how host shifts occur. Here we describe the inheritance of adult host acceptance (oviposition) in three closely related species of Yponomeuta Latreille (Lepidoptera: Yponomeutidae), and their interspecific hybrids. Yponomeuta cagnagellus (Hübner), a specialist on Euonymus europaeus L. (Celastraceae), Y. malinellus Zeller, a specialist on Malus spp. (Rosaceae), and Y. padellus (L.), oligophagous on a number of Rosaceae, were tested for their acceptance of parental hosts in choice tests. Acceptance of E. europaeus is semi‐dominant in hybrids of Y. cagnagellus×Y. padellus, and in hybrids of Y. cagnagellus×Y. malinellus. The dominance of this acceptance was confirmed in oviposition tests with backcross hybrids: backcross hybrids F1 × Y. cagnagellus oviposited mainly on E. europaeus and F1 × Y. padellus still deposited more than half of their egg masses on E. europaeus. Reciprocal hybrids did not differ in their host acceptance, indicating that the trait is autosomal. We further studied the effect of larval food on adult host acceptance (‘Hopkins host selection principle’) in split full‐sib F1 families. Larval diet influenced oviposition only in one of two hybrid crosses. The F1 hybrid of Y. padellus× Y. cagnagellus, reared on Prunus spinosa L., deposited a significantly lower percentage of egg masses on E. europaeus compared to their full‐sib sisters fed with E. europaeus. We did not find this in the reciprocal cross. However, still more than half of the egg masses are deposited on E. europaeus by hybrids that have no experience on this host. We conclude that the semi‐dominant character of acceptance of E. europaeus and a tendency of Rosaceae‐feeding Yponomeuta to deposit egg masses on this host may have created the opportunity for the host shift of the predecessor of Y. cagnagellus from Rosaceae to the Celastraceae. This shift may have been further facilitated by a weak tendency of adults to oviposit on their larval food source.

The Life and Death of Hopkins' Host-Selection Principle

Hopkins’ host-selection principle (HHSP) refers to the observation that many adult insects demonstrate a preference for the host species on which they themselves developed as larvae. The meaning of HHSP has changed significantly since its first proposal in 1916. This review considers how the meaning of HHSP has changed over time and considers the various mechanisms that could contribute to a behavioral bias for the developmental host. The assumption that HHSP implies that the behavior of adult insects is conditioned by larval experience has resulted in widespread condemnation of HHSP. Despite a great deal of attention, there is still very little convincing evidence for preimaginal conditioning of host choice in insects. But growing evidence indicates that genetic variation in behavior and conditioning during the life span of an adult insect can contribute to a preference for the host on which an insect developed. Insects can acquire adult oviposition or feeding preferences through exposure to chemical residues from the environment of earlier life history stages. The concepts of host races and host fidelity have become familiar and acceptable, while the association of HHSP with preimaginal conditioning has led to a general rejection of the term.

Hopkins host-selection in Nasonia vitripennis and its implications for sympatric speciation

The operation of the Hopkins host-selection principle in the host-selection behaviour of the parasitoid wasp Nasonia vitripennis on three dipteran host species was tested. In order to determine whether larval conditioning influenced adult ovipositional preference, the parasitoids were reared on and then offered choices between host species in two pairwise combinations, Phormia regina/Phaenicia sericata and P. regina/Musca domestica. Hopkins host-selection was evident in the latter combination only. Preference for a given host is not reinforced by conditioning over several generations. The conditioning was not strong enough to serve as a primary isolating mechanism in the speciation process as suggested by Thorpe (1938, 1945), though it could be important as a secondary isolating mechanism.

Host Selection in Pyrausta nubilalis, Hübn.

During the last few years a number of papers have been published by entomologists in connection with the hypothesis known as the “ Hopkins host-selection principle.” This principle, as defined by Dr. A. D. Hopkins himself, is that an insect species that breeds in two or more hosts will continue to breed in the host to which it has become adapted. Thus, according to this author, the mountain pine beetle, Dendroctonus monticola, will destroy mountain pine, yellow pine, lodgepole pine and sugar pine, but if it becomes established in one species of pine through many generations, the beetles on emergence show a decided preference for the species in which they have bred and will not, in fact, attack any other. In 1922 Craighead published a paper giving the results of experiments carried on during a number of years with about a dozen species of Cerambycids. He states that in practically all the species studied the adults show a marked predilection for the host in which they have fed as larvae, provided that they are not deterred by other factors. Continued breeding in a given host is said to intensify the preference for that host. With some beetles whose larvae can be transferred to another species of plant and successfully reared therein, this association with the new host for a year, or even less, during the latter part of the larval life is said to determine a preference for this in the resulting adults. The author believes that his experiments may indicate the mode of origin of certain closely related species or varieties. The conclusions at which he has independently arrived were long ago suggested by Walsh. That new forms do not thus arise more rapidly in Nature, Craighead considers to be due to the high mortality of the young larvae in the new hosts.

Hopkins host-selection principle as related to certain Cerambycid beetles

Hopkins host-selection principle as related to certain Cerambycid beetles