寄主經驗對四紋豆象寄主偏好之作用及機制

Effects of Experience on Host Preference of Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) and its mechanisms

戴孝閔(Shiau-Min Dai)

指導教授 ： 洪淑彬

國立臺灣大學/生物資源暨農學院/昆蟲學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.03044

摘要

豆象為內食性昆蟲，其成蟲出豆前均在豆中生活，有足夠機會獲取寄主特性的資訊，進而可能影響成蟲之寄主選擇，本研究首先以飼養於不同寄主之四紋豆象探討成蟲前經驗對其寄主偏好之作用。紅豆或綠豆飼養之四紋豆象，以不同寄主豆進行非自由選擇產卵偏好試驗時，顯示其對各種寄主之接受度並無顯著差異﹔若同時供應不同寄主進行自由選擇產卵偏好時，則四紋豆象顯著偏好紅豆或黑豆，但以不同寄主飼養或羽化自不同環境的四紋豆象對不同寄主之偏好程度並無差異，顯示四紋豆象之幼蟲期或成蟲早期寄主經驗不會影響成蟲之寄主偏好。因此，進一步以轉換寄主方式測試成蟲之寄主經驗對寄主偏好的作用，及成蟲經驗持續之時間。在紅豆寄主上產過卵的四紋豆象移到綠豆寄主時，其產卵數會顯著降低﹔但單獨經歷綠豆寄主之四紋豆象於再次接觸綠豆寄主時則不會在綠豆上有抑制產卵的現象；而在綠豆上產卵後再遭遇紅豆時，其產卵數則顯著增加。因此成蟲時期所經歷的寄主經驗則會對之後的寄主偏好產生影響。本文首次報導成蟲於紅豆上所學習到的成蟲經驗至少能持續兩個半小時。此外，試驗發現寄主比例與寄主大小也會影響寄主偏好。挑選大顆綠豆與小顆紅豆進行自由選擇產卵試驗時，四紋豆象在綠豆上的產卵比例顯著高於提供正常紅豆與綠豆自由選擇產卵試驗者，但四紋豆象仍舊顯著偏好在紅豆上產卵，顯示寄主種類是影響偏好較重要的因子。若將紅豆種皮去除時，四紋豆象對紅豆的偏好會顯著降低，因此推測紅豆種皮上有產卵刺激物質，促使四紋豆象增加對紅豆的寄主偏好。

關鍵字

四紋豆象 ； 寄主偏好 ； 寄主經驗

並列摘要

The seed beetle, Callosoburcus maculatus (F.) is an endophagous insect. The beetle lived in the seed before adult emergence, the larva or the adult thus has enough opportunity to obtain the information of host traits, and it may influence the host preference of the adult. In this study, adults emerged from various hosts were used to test whether larval or pre-adult experience affect host preference of the adult. The results showed that there is no significant difference on the host acceptance by seed beetles that reared on adzuki bean or mung bean, when no-choice tests of host acceptance on adzuki bean, mung bean and black soybean were conducted. But adults exhibited significant difference of host preference, when free choice tests of host preference on different seeds were studied. However, the host preference has no significant difference between adults that reared on adzuki bean and mung bean or emerged from adzuki and mung bean powder, these results indicate that the larval or pre-adult host experience does not influence the adult host preference. Whereas, adult host experience did affects her host preference. Therefore, host transfers were used to test the effect and the duration of adult experience on host preference of the adult. The number of eggs laid on host drastically decreased when adults transferred from adzuki bean to mung bean, but the adult does not decrease her number of eggs laid on mung bean when transfer from mung bean. If the adult was transferred from mung bean to adzuki bean, the number of eggs laid significantly increased. In this study, we first found also that the effect of host experience on adzuki bean could last 2.5 hours. Besides, we provide evidence to support that the proportion of host and the size of host would affect host preference of the adult. When big mung bean and small adzuki bean were provided simultaneously to make a free choice test of host preference, adults laid more eggs on big mung bean compare to the test with normal size of adzuki bean and mung bean. But the proportion of eggs on small adzuki bean was still significantly higher than that on big mung bean. It shows that the host species is a more important factor that affects host preference. Adults decreased the preference of adzuki bean after removing the seed coat, suggested that there is oviposition stimuli on seed coat of adzuki bean that raise the host preference of adzuki bean.

並列關鍵字

Host preference ； Experience ； Callosobruchus maculatus

參考文獻

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