I spend a lot of time studying ambush bugs.  While I certainly don't claim to be the expert, I imagine that, at the moment, I am among only a few people who have studied these bugs in any detail.  So I guess it is my duty share what I know (or at least point you to a direction/reference).  

I maintain this section as a summary of the natural history of these bugs for the sake of ‘everyday naturalists’.  Hopefully, this also means that I can stay on the radars of other natural historians out there - several have contacted me in the past with invaluable information.  If you want more technical/detailed information about my work, please visit my publications page.  If you have questions or information to share, please contact me.

My knowledge is mostly restricted to the currently recognized species in Southern Ontario (Phymata americana & pennsylvanica; but also check out this *nice blog post* on the issues surrounding Identification), though I have been getting a bit more familiar with the other species in the group.  

Scroll over the images to see some tidbits.

CLASSIFICATION. Ambush bugs (subfamily Phymatinae) belong to the Order Heteroptera (True Bugs) and the Family Reduviidae (Assassin Bugs). For real expertise on taxonomy of Assassin Bugs (including Ambush Bugs) check with my colleague, Christiane Weirauch at University of California Riverside.

HABITS. These bugs are sit-and-wait predators. They hide among flowers and use their powerful claw-like forelimbs to capture other insects. They have a rostrum (sucking mouthparts), with which they inject paralyzing and digestive enzymes into their prey. They then use this straw-like organ to drink up the insect "soup".

LIFE CYCLE. Phymata americana has one generation per year. Eggs are laid on plant material in the fall and survive through the winter. Nymphs hatch in the early summer and 5 molts (instars) later, they emerge as adult bugs. Ambush bugs are predaceous at all stages.

MATING BEHAVIOUR. Adult males and females are frequently found in the characteristic "coupled" position shown in this picture. From this position they engage in a number of courtship behaviours while (presumably) guarding their potential mate from other males. From this position, bugs communicate using stridulatory (vibrational) signals. If courtship is successful, bugs copulate in a sideways position.

DIVERSITY. There are over 100 species in the genus Phymata. As you can see from this picture of 7 species and subspecies, size and colour differences between females (two left columns) and males (two right columns) are quite common. We don't yet fully understand the evolutionary causes of these sex- and species-differences.

SEXUAL DIMORPHISM. In one species (P. americana), the sexes are quite different in size and in the degree of dark colouration. In this species, dark male colouration is advantageous for mating. Curiously, this advantage stems from thermoregulatory benefits (darker males have greater mate searching success).