Hartke Tamara R, Rosengaus Rebeca B
Northeastern University Biology Department, 360 Huntington Avenue, Boston, MA 02115, USA.
Naturwissenschaften. 2011 Sep;98(9):745-53. doi: 10.1007/s00114-011-0823-y. Epub 2011 Jul 15.
The sympatric neotropical termites Nasutitermes corniger and Nasutitermes ephratae are clearly distinguishable based on morphology, nest architecture, defensive secretion composition, and molecular markers. However, given the extensive ecological, geographical, and behavioral overlap of these closely related species, the potential for interbreeding may exist. To explore this possibility, heterospecific pairs were formed experimentally to examine courtship and colony-establishment behaviors, and reproductive potential. Courtship and nest construction behavior occurred in heterospecific pairs in a similar manner to that of conspecific pairs. Survival of pairs depended upon the species of the female partner. N. ephratae females paired with N. corniger males produced as many offspring as conspecific pairs. N. corniger females mated to N. ephratae males, however, produced significantly fewer offspring at 60 days post-establishment than the reciprocal cross or conspecific N. ephratae or N. corniger pairs. This was also the only pairing in which any aggression was observed. Heterospecific pairs and groups formed in mate choice mesocosms, suggesting that species recognition between these two termites is not an important aspect of mate choice. Overall, species mismatch tolerance and hybrid offspring viability are high. The present data, together with previous evidence from defensive secretions and isozyme analysis, suggest that hybridization may periodically occur in nature, and that reproductive barriers between these two species may be incomplete. Hybridization could provide a rare but important source of genetic diversity and may ensure mating opportunities for the more abundant sex of alates in each species.
同域分布的新热带白蚁玉米鼻白蚁（Nasutitermes corniger）和埃氏鼻白蚁（Nasutitermes ephratae）基于形态、巢穴结构、防御分泌物组成和分子标记可明显区分。然而，鉴于这些近缘物种在生态、地理和行为上存在广泛重叠，可能存在杂交的可能性。为了探究这种可能性，通过实验形成了异种配对，以检查求偶和群体建立行为以及繁殖潜力。异种配对中的求偶和筑巢行为与同种配对的方式相似。配对的存活取决于雌性伴侣的物种。埃氏鼻白蚁雌性与玉米鼻白蚁雄性配对产生的后代数量与同种配对一样多。然而，玉米鼻白蚁雌性与埃氏鼻白蚁雄性交配后，在建立配对60天后产生的后代明显少于反交或同种的埃氏鼻白蚁或玉米鼻白蚁配对。这也是唯一观察到有攻击行为的配对。在配偶选择微宇宙中形成了异种配对和群体，这表明这两种白蚁之间的物种识别不是配偶选择的重要方面。总体而言，物种错配耐受性和杂交后代活力较高。目前的数据，连同先前来自防御分泌物和同工酶分析的证据，表明杂交可能在自然界中周期性发生，并且这两个物种之间的生殖隔离可能不完整。杂交可以提供一种罕见但重要的遗传多样性来源，并可能确保每个物种中数量较多的有翅成虫性别的交配机会。
