Introduction

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) vector Huanglongbing (HLB) caused by the bacterium Candidatus Liberibacter spp., the worst disease of citrus worldwide. In heavy infestations can kill the psyllid vegetative buds of growing plants or cause leaf abscission (^{Michaud, 2004}). Also cause direct damage to the foliage, which facilitates the deformation of leaves and affects yield potential. The HLB management should be based on the timely removal of infected trees, use of healthy plants from certified nurseries and protected in the management of vector populations D. citri (^{da Graca, 1991}; ^{Chiou, 1998}; ^{da Graca y Korsten, 2004}; ^{Bové, 2006}; ^{National Research Council, 2010}).

In Mexico, it has driven the integrated management of insect through the implementation of a regional plan, the scheme provides for chemical control to reduce or eliminate vector populations and biological control through massive release of parasitoid Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae), considered the main natural enemy of D. citri (^{Chien et al., 2001}; ^{Etienne et al., 2001}; ^{McFarland and Hoy, 2001}; ^{Aubert, 2008}). At home there are two breeding centers parasitoid and while maintaining a considerable production thereof is insufficient to meet the requirement of the citrus regions where they are produced (Yucatán's peninsula and region the Pacífico's lemon).

Moreover, there are numerous predators attacking D. citri populations. Usually the most abundant are some species of lacewings Chrysoperla and Ceraeochrysa gender also coccinellid (^{Cortez-Mondaca et al., 2010}; ^{Lopez-Arroyo et al., 2010}) as the gray ladybug Olla v-nigrum (Mulsant), which shows a high potential to suppress pest populations (^{Michaud, 2004}). In Mexico there is at least one laboratory reproduction of beneficial insects in each entity in most of them playing some kind of Chrysoperla (^{Bahena, 2008}, ^{SENASICA, 2011}).

This infrastructure and equipment can be utilized to reproduce some of the species associated with D. citri on citrus. This study was conducted in order to determine the species of Chrysopidae associated with the Asian citrus psyllid in commercial orchards, in the state of Sinaloa and evaluate the ability of predation in the stages of egg, girls nymphs and large Asian psyllid citrus.

Materials and methods

The study was conducted in two stages:

Stage I. Collection and identification of species associated Chrysopidae Asian citrus psyllid in commercial orchards. It was conducted under field conditions using pickings lacewing adults and reproduction of the species obtained was performed at the Laboratory Breeding Beneficial Insects of the Local Board of Plant Protection Carrizo Valley, located in Villa Diaz Ordaz, Sinaloa. During the months of july 2010 to september 2011.

Were performed 12 adult lacewing pickings with entomological net in six commercial orchards of orange Citrus sinensis Osbeck and lemon Mexican Citrus aurantifolia Swingle located in the north, in the town of Ahome; in the center, in the town of Mocorito; east, in the municipality of Sinaloa de Leyva; and in the south, in the town of La Cruz de Elota, the state of Sinaloa, in July 2010, March 2011, August 2011 and September 2011 (Table 1). Lacewing adults captured by three to five hours hits an entomological net in different parts of each citrus orchard in each sampling date, they were confined in cages and transported to the laboratory breeding of beneficial insects The Local Board Plant health Carrizo Valley, where they were given food and waited for them to reproduce (F1), third instar larvae were identified to species based on the taxonomic keys ^{Lopez-Arroyo et al. (2008)} and ^{Tauber and Leon (2001)}, using a stereoscopic microscope.

In 3520 larvae obtained in the first generation (F1) was randomly identified 550 larvae (15.6%), product screenshots July 2010; 300 larvae of 653 (45.9%), 300 larvae of 387 (77.5%) and 604 larvae 1 573 (38.4%) of each of the three sacks in March 2011; Larvae produced 233 233 (100%) of the capture of august 2011; and 718 larvae, product of two catches september 2011, the total (100%) were inspected.

The results of the samplings were separately subjected to a one-way ANOVA, considering the sampling dates as repetition. The average obtained for each species was applied the Tukey test (5%) (^{SAS, 2009}), the relative abundance of each species of lacewing obtained (^{Magurran, 1988}) was calculated and graphic results were formulated. In the laboratory of CEVAF reference specimens are preserved.

Stage II. Capacity assessment predation Ch. Carnea Stephens, Ch. Rufilabris, Ch. Comanche and C. valida on some of the immature stages of D. citri. This stage was carried out under laboratory conditions at the National Institute of Agricultural and Livestock Forestry Research (INIFAP) -Campo Experimental Valle del Fuerte (CEVAF), seven tests were conducted predation, four eggs, one with girls nymphs (first and second instar) and two large nymphs (fourth and fifth instar) during july and august 2011.

Predators. second instar larvae of the green lacewing species existing laboratory breeding of beneficial insects, the Local Board of Plant Protection Carrizo Valley, at the time of each test were evaluated. Evaluated lacewing larvae adults obtained corresponded to identify species Chrisopidae (^{Cortez-Mondaca et al., 2011}).

Preys. For testing highly infested seedlings with D. citri were collected from five to 10 cm in length for commercial trees citrus groves and backyard trees, usually Mexican lime for immature stages of the Asian citrus psyllid and they were counted, to establish a certain number of them in each outbreak. With an entomological needle is removed from each outbreak different development states the purpose of evaluation, only specimens of age who wanted to assess in each event were left. Outbreaks usually containing 100 copies of D. citri, were placed in a plastic petri dish of 13 cm in diameter and 2 cm, and exposed to a second instar larva, previously isolated and subjected to fasting for 24 h (Cortez et al., 2002). The larva fasting was placed directly on containing outbreaks dams; then shoots were examined at different intervals of time, for counting the number of surviving specimens, eggs, nymphs or large nymphs girls. The difference between before and after the inspection was the number of prey consumed.

For each kind of larva stage of the dam and four replications of the test were performed. The results were subjected to a one-way ANOVA; the averages were applied Tukey test (5%) (^{SAS, 2009}).

Results

Stage I. Determination of the number of species associated Chrysopidae the Asian citrus psyllid. A total catch of 2 337 adult lacewing commercial citrus orchards in the state of Sinaloa, Mexico was obtained. The number of adults captured by orchard and date of capture, was variable, from 52 specimens in Dolores Hidalgo, Ahome, on July 6, 2010, 400 specimens from Orchard Caimanero Mocorito on 25 March 2011. Generally the number of catches by date and orchard were about 150 adults (Table 1).

Species identification. In the first three dates grouped catches, august 7, 2010, 16 and 17 march 2011, Ch. Comanche was the predominant species (Figure 1), while the dates of march 25 and august 26, and on september 7, 2011, C. valid was the most abundant. Ch. Carnea and C. Claveri were the rarest species, the first one occasion captured on the first sample and the second in the last two dates and places of capture. The results of the ANOVA showed significant difference in the prevalence of C. valid and Ch. Comanche about Ch. Rufilabris, C. Claveri and Ch. Carnea (p< 0.0004). Whereas in the calculation of the relative abundance of each species, C. validates showed nearly half of the total captured specimens (0.495), followed closely by C. Comanche (0447), together accounted for 0.942 of relative abundance; all other species in total amounted to only 0.057 (Figure 2).

Figure 1 Number of specimens Crhysopidae identified to species, adult captured in citrus orchards in Sinaloa, Mexico. 

Figure 2 Relative abundance of species Chrysopidae in commercial orchards of orange and Mexican lime in Sinaloa, Mexico. 

Stage II. Capacity assessment predation Ch. carnea, Ch. rufilabris, Ch. comanche and C. valida. In four tests predation on eggs of D. citri no significant difference between treatments (p> 0.05) was detected; however, in all tests Ch. rufilabris showed increased consumption of dams in the early hours of exposure, after five or six hours had consumed 90% or more of the available eggs. In the second test, Ch. Comanche consumed more than Ch. Carnea in the first four readings predation (Figure 4). In the third evaluation Ch. Carnea consumed more egg in the first three readings of predation compared to Ch. Comanche (Figure 5). In the latest assessment of egg predation Ch. Comanche, it predated C. valid only in the first five readings (Figure 6). Lacewing evaluated species consumed nearly all of D. citri eggs before or 24 h exposure (Figures 4, 5 and 6).

Figures 3, 4, 5 and 6 Consumption of eggs Diaphorina citri lacewing species of broodstock from citrus groves. 

The only assessment girls nymphs (first and second instar) with Ch. rufilabris, Ch. comanche and C. valida, significant difference (p< 0.001) was obtained in the first five readings of predation. Girl consumption D. citri nymphs was significantly different between Ch. comanche and Ch. valid in the first five readings mortality.; and about Ch. comanche and Ch. rufilabris significant difference in consumption of nymphs in the first and third reading predation. Ch. comanche consume 99 specimen of D. citri to four hours of exposure (third reading) of dams The three species preyed nymphs girls total 24 h of exposure (Figure 7).

Figure 7 Consumption small Diaphorina citri nymphs lacewing species of broodstock from citrus groves. 

In the first test of predation capacity Ch. Rufilabris, Ch. Comanche and Ch. Carnea on large nymphs (fourth and fifth instar) of D. citri, no significant difference between the readings of predation (p< 0.001) was detected. The consumption of prey by Ch. rufilabris was higher in the first four readings (1, 2, 3 and 5 h), but at 24 h Ch. comanche consumption exceeded the other two species. Among Ch. comanche and Ch. carnea the difference in consumption was reduced in the four readings prumras predation, but all readings was higher for the former species. After 24 h of exposure, all species consumed more than 90 large nymphs of D. citri on average (Figure 8). In the second test, with evaluation of Ch. rufilabris, Ch. comanche, Ch. carnea and C. valid, significant difference between treatments (p< 0.001) was observed Ch. comanche concerning C. valida and Ch. carnea, but compared to Ch. rufilabris at first reading (a one hour exposure prey-predator). In other readings predation no significant difference between treatments was determined even though the average values of predation is different (Figure 9), protruding Ch. Comanche readings 5, 6 and 7 h exposure. C. valida showed the lowest consumption of prey, especially in the first three readings of predation, in other consumption was close to that of Ch. carnea (Figure 9).

Figure 8 and 9. Consumption of large nymphs Diaphorina citri lacewing species of broodstock from citrus groves. 

Discussion

Conclusions

The higher prevalence of C. comanche in citrus, combined with the ability to prey consumption suggest that Ch. comanche may have greater chance of success against the Asian citrus psyllid in Sinaloa, Mexico.

The use of lacewing is proposed as an alternative that would reduce exclusive dependence on chemical control for controlling D. citri. Also, avoid the risks inherent in the use of toxics environment.